My 1996 4.0L SJX will not start. I was able to get one start out of it. It idlled, rough, for about two minutes then quit. I have been unable to start it since. This happened once before. I had to put the car on a trailer and take it 100 miles to a certified Jag mechanic. Very costly.

I will have to do my own maintenance or get rid of the car. I figure that I need to purchase an OBD II scanner to begin with.

There are a number of them on the market. Can anyone recommend what brand will be the most user friedly and dependable?

 

You need to find out if its a fuel issue or an ignition issue, while the trouble codes may give you a clue as to wear to begin looking, they often become a debilitating crutch for some people.

Personally my favorite that I have ever purchased was a 15 or so dollar bluetooth OBDII adapter. I set it up to read on my girlfriends galaxy because my stupid iphone 4 locks bluetooth, and I can scan it with a couple different downloadable programs that give data only gleaned through a $100++ scanner, plus you can use it anywhere outside the car since its wireless.

 

I own that one. Works fine.

I also have a more robust reader that works off of my laptop. It helps me read oxygen sensors, throttle position, etc.

I'd say for now, this one might get you started.

I would also consider getting a wireless bluetooth plug like this one (which I also own):


I bought that one from eBay for less than Amazon. It allows me to hook up my Laptop to the car. I think you'll find some free programs that will allow you to pull codes, but not much else (for free).

 

When this happened before, it was an ignition issue. The mechanic said he had to try substituting control modules until it would finally start.
Will the OBD II scanner indicate which control module would be affected?

 

No, the scanner will only give a trouble code that will send you in the general direction of the fault.
Have you tried spraying some sort of fuel, such as carburetor cleaner, or starting fluid, into the throttle body to see if it will fire? That usually will tell you if your problem is no spark, or no fuel.